Adsorption of Omeprazole on Biobased Adsorbents Doped with Si/Mg: Kinetic, Equilibrium, and Thermodynamic Studies

This paper proposes an easy and sustainable method to prepare high-sorption capacity biobased adsorbents from wood waste. A biomass wood waste (spruce bark) was employed to fabricate a composite doped with Si and Mg and applied to adsorb an emerging contaminant (Omeprezole) from aqueous solutions, as well as synthetic effluents loaded with several emerging contaminants. The effects of Si and Mg doping on the biobased material’s physicochemical properties and adsorptive performance were evaluated. Si and Mg did not influence the specific surface area values but impacted the presence of the higher number of mesopores. The kinetic and equilibrium data presented the best fitness by the Avrami Fractional order (AFO) and Liu isotherm models, respectively. The values of Qmax ranged from 72.70 to 110.2 mg g−1 (BP) and from 107.6 to 249.0 mg g−1 (BTM). The kinetic was faster for Si/Mg-doped carbon adsorbent, possibly due to different chemical features provoked by the doping process. The thermodynamic data showed that the adsorption of OME on biobased adsorbents was spontaneous and favorable at four studied temperatures (283, 293, 298, 303, 308, 313, and 318 K), with the magnitude of the adsorption correspondent to a physical adsorption process (ΔH° < 2 kJ mol−1). The adsorbents were applied to treat synthetic hospital effluents and exhibited a high percentage of removal (up to 62%). The results of this work show that the composite between spruce bark biomass and Si/Mg was an efficient adsorbent for OME removal. Therefore, this study can help open new strategies for developing sustainable and effective adsorbents to tackle water pollution.


Introduction
Nowadays, the pollution of water bodies is a tremendous issue for the environment, animals, and human beings, and due to the intense human and industrial activities, this issue has only grown [1,2]. Among many different pollutants in natural waters, a new class, so-called emerging contaminants (ECs), has gathered enormous concerns from environmental researchers due to their deleterious effects on living beings, even at very small concentrations [3,4]. ECs are different compounds, such as pharmaceuticals and

Characterization of the Adsorbents
Textural properties such as SSA and porosity (meso-and micropore features) are very important for determining any adsorbent's quality that will impact its adsorptive performances [22,23]. The textural characteristics of the biobased adsorbents (BP and BTM) are summarized in Table 1. It shows that the chemical dopants used did not influence the SSA value. Both samples exhibited SSA values of 205 and 202 m 2 g −1 for BP and BTM, respectively. Compared with the literature, Deng et al. [24] prepared corncob biochars doped with MgCl 2 and obtained specific surface areas ranging from 52.41 to 174.29 m 2 g −1 .
Although there was no difference in SSA values, the doping Si/Mg did influence the mesopore contribution compared to the pristine biobased carbon. The mesopores are responsible for adsorbing molecules larger in size, and also it could improve the uptake of smaller molecules since each pore of the material can accommodate agglomerates of small molecules [12,14]. However, the results show that both adsorbents are highly microporous, which is a good characteristic that may facilitate the diffusion of smaller adsorbate molecules such as OME into the adsorbents' pores [25]. The surface morphological characteristics of BP and B-Si-Mg adsorbents are evaluated by SEM images (shown in Figure 1). BP exhibits a more irregular surface with no apparent porosity. In contrast, BTM showed a smoother surface with several small holes unveiling some developed porous structures related to a high surface area. On the doped biochar's surface, it is possible to observe some white dots, which are the dopants attached (fused) to the biochar carbon matrix. It is reported that adsorbents rich in both physical (irregular morphology) and chemical (by introducing Si/Mg atoms) defects can be beneficial in adsorbing OME because these defects act as adsorptive sites that can boost the adsorption through pore filling and electrostatic interaction (further explained ahead in the mechanism of adsorption) [11,13,17]. Complementarily to SEM, EDS mapping of Si ( Figure 1c) and Mg ( Figure 1d) is also explored. EDS quantification of the elements indicated 18.4% and 10.7% of Si and Mg, respectively. The elements mapping of the composite surface confirmed the presence of two elements (Si and Mg), showing their uniform distribution over the carbon structure (see Figure 2c,d).
Molecules 2023, 28, 4591 3 of 15 molecules since each pore of the material can accommodate agglomerates of small molecules [12,14]. However, the results show that both adsorbents are highly microporous, which is a good characteristic that may facilitate the diffusion of smaller adsorbate molecules such as OME into the adsorbents' pores [25]. The surface morphological characteristics of BP and B-Si-Mg adsorbents are evaluated by SEM images (shown in Figure 1). BP exhibits a more irregular surface with no apparent porosity. In contrast, BTM showed a smoother surface with several small holes unveiling some developed porous structures related to a high surface area. On the doped biochar's surface, it is possible to observe some white dots, which are the dopants attached (fused) to the biochar carbon matrix. It is reported that adsorbents rich in both physical (irregular morphology) and chemical (by introducing Si/Mg atoms) defects can be beneficial in adsorbing OME because these defects act as adsorptive sites that can boost the adsorption through pore filling and electrostatic interaction (further explained ahead in the mechanism of adsorption) [11,13,17]. Complementarily to SEM, EDS mapping of Si   Figure 2 shows the Raman analysis for both samples; Raman spectroscopy gives valuable information on the order/disorder and degrees of biochars graphitization [26,27]. Figure 2 shows that for both samples, two characteristic peaks at 1335 cm −1 (D-band) and 1600 cm −1 (G-band). The D-band is related to C atoms of defects or disordered structures, typically dominant in amorphous carbon materials derived from biomass, while G-band represents carbon atoms with an sp 2 electronic configuration in graphite structures [28-  Figure 2 shows the Raman analysis for both samples; Raman spectroscopy gives valuable information on the order/disorder and degrees of biochars graphitization [26,27]. Figure 2 shows that for both samples, two characteristic peaks at 1335 cm −1 (D-band) and 1600 cm −1 (G-band). The D-band is related to C atoms of defects or disordered structures, typically dominant in amorphous carbon materials derived from biomass, while G-band represents carbon atoms with an sp 2 electronic configuration in graphite structures [28][29][30]. In addition, from the Raman spectrum, the ratio between D and G peaks (I D /I G ) is often employed to determine the degree of graphitization of the biochar. respectively [31,32]. The (002) peak is attributed to the packed carbon layers and amorphous and aliphatic structures [31,32]. The broad peak at 44° is associated with (100) diffractions of graphitic carbons, indicating a certain degree of aromatization in the BP structure. However, for the BTM, the broad peak at (100) disappeared, indicating a higher degree of amorphization, possibly provoked by the incorporation of Si [32]. In addition, however, some small crystalline peaks can be seen related to MgO [24].

Kinetic of OME Adsorption on BP and BTM Adsorbents
In an adsorption process, the kinetic is a crucial step to ensure that the system reaches the saturated adsorption capacity and for understanding the mechanism(s) acting in the process regarding diffusion and mass transport in the adsorption system [29][30][31][32][33]. Figure  3 and Table 1 show the kinetic curves and parameters for OME removal onto biobased adsorbents, respectively. The same trend was observed for both adsorbents, with a rapid increase in their uptake within 25 min, which seemed to reach the equilibrium (see Figure  3). The rapid equilibrium highlights the high affinity between adsorbents and adsorbate.
The nonlinear pseudo-first-order (PFO), pseudo-second-order (PSO), and Avramifractional-order (AFO) models were used to analyze the fitness of the kinetic data (see Table 2 and Figure 3). It is essential to understand the adsorption rate to design the adsorbents' application. In this study, nonlinear models were used, which offer a good fitting of the data. PFO and PSO models suppose that the interaction between adsorbate and adsorbent can be physical or chemical adsorption, following an adsorption kinetic of first or second order, respectively. However, the AFO model suggests a fractional order of the adsorption kinetic. The models' fitness was evaluated using the adjusted R 2 adj, SD, and BIC values [14,25,34] (see Supplementary Materials). The carbon material doped with the Si/Mg presented a slightly higher I D /I G (3.6) compared to pure carbon sample BP (3.2) (see Figure 2a), indicating little more defects in its structure. Many reports suggest that adsorbents rich in defects, which could mean more adsorption sites, can have their adsorptive properties boosted [11]. As previously mentioned, these defects can be both physical and chemical, which are responsible for boosting the adsorbent adsorptive properties through different mechanisms (pore filling and electrostatic interactions, further explained ahead in Section 2.5). Therefore, Si/Mg dopants helped increase the adsorption sites in the BTM adsorbent. Figure 2b shows the X-ray diffraction pattern of the adsorbent materials. Important differences are observed between both patterns (see Figure 2b). BP shows two prominent broad peaks at 2θ = 24.5 • and 44 • , which are associated with the (002) and (100) planes, respectively [31,32]. The (002) peak is attributed to the packed carbon layers and amorphous and aliphatic structures [31,32]. The broad peak at 44 • is associated with (100) diffractions of graphitic carbons, indicating a certain degree of aromatization in the BP structure. However, for the BTM, the broad peak at (100) disappeared, indicating a higher degree of amorphization, possibly provoked by the incorporation of Si [32]. In addition, however, some small crystalline peaks can be seen related to MgO [24].

Kinetic of OME Adsorption on BP and BTM Adsorbents
In an adsorption process, the kinetic is a crucial step to ensure that the system reaches the saturated adsorption capacity and for understanding the mechanism(s) acting in the process regarding diffusion and mass transport in the adsorption system [29][30][31][32][33]. Figure 3 and Table 1 show the kinetic curves and parameters for OME removal onto biobased adsorbents, respectively. The same trend was observed for both adsorbents, with a rapid increase in their uptake within 25 min, which seemed to reach the equilibrium (see Figure 3). The rapid equilibrium highlights the high affinity between adsorbents and adsorbate.
The nonlinear pseudo-first-order (PFO), pseudo-second-order (PSO), and Avramifractional-order (AFO) models were used to analyze the fitness of the kinetic data (see Table 2 and Figure 3). It is essential to understand the adsorption rate to design the adsorbents' application. In this study, nonlinear models were used, which offer a good fitting of the data. PFO and PSO models suppose that the interaction between adsorbate and adsorbent can be physical or chemical adsorption, following an adsorption kinetic of first or second order, respectively. However, the AFO model suggests a fractional order of the adsorption kinetic. The models' fitness was evaluated using the adjusted R 2 adj , SD, and BIC values [14,25,34] (see Supplementary Materials). Lower SD and higher R 2 adj values suggest that the q experimental values are much closer to q provided by the models. Thus, it better describes the experimental values, suggesting the model's better fitness. As seen in Table 2, AFO exhibited the highest R 2 adj and lowest SD values and, therefore, better suitability to describe the kinetic adsorption of OME on both adsorbents. Moreover, the Bayesian Information Criterion (BIC) was also employed to corroborate the suitability of the kinetic model. Lima et al. (2021) [21] reported that if the difference between two BIC values (ΔBIC) of the models is ≤2.0, it means that the difference between the two models is not significant. For ΔBIC ≥ 10, it can be stated without any doubt that the model with a lower BIC value presented the best suitability. Table 2 shows that the ΔBIC values between the AFO model and PFO were 33.29 and 8.57, and the BIC differences between the AFO model and PSO were 56.71 and 33.33 for BP and BTM, respectively. This confirms that the AFO kinetic model for the OME molecules adsorption is the best-fitted. The adsorption order for the OME molecules on BP was 1.513, a value closer to 2, while nAV for the adsorption of OME molecules onto BTM was 0.8409, a value close to 1.
The AFO is widely reported in the literature, and it suggests a complex process with multiple adsorption pathways, with dynamic/different mechanism (s), while adsorption occurs [35,36]. This process presents multiple kinetic orders instead of one, represented by nAV, which usually has a fractional value [35,36]. Thus, evaluating t1/2 and t0.95 becomes important for comparing different kinetic models (see Table 2) [19,20,25,[33][34][35]. The t0.95 is the time to reach 95% of total saturation, and t1/2 is the time to reach 50%. Considering that the AFO presented the best fitness, its values for t1/2 and t0.95 were 8.32 min and 21.87 min, and 3.27 min and 18.65 min for BP and BTM adsorbents. It shows that the kinetic was faster for BTM, possibly due to different chemical features provoked by the doping with Si/Mg [24]. Short times to attain 95% saturation are obtained for carbon-based materials to uptake emerging organic molecules [12,14,20].   Lower SD and higher R 2 adj values suggest that the q experimental values are much closer to q provided by the models. Thus, it better describes the experimental values, suggesting the model's better fitness. As seen in Table 2, AFO exhibited the highest R 2 adj and lowest SD values and, therefore, better suitability to describe the kinetic adsorption of OME on both adsorbents. Moreover, the Bayesian Information Criterion (BIC) was also employed to corroborate the suitability of the kinetic model. Lima et al. (2021) [21] reported that if the difference between two BIC values (∆BIC) of the models is ≤2.0, it means that the difference between the two models is not significant. For ∆BIC ≥ 10, it can be stated without any doubt that the model with a lower BIC value presented the best suitability. Table 2 shows that the ∆BIC values between the AFO model and PFO were 33.29 and 8.57, and the BIC differences between the AFO model and PSO were 56.71 and 33.33 for BP and BTM, respectively. This confirms that the AFO kinetic model for the OME molecules adsorption is the best-fitted. The adsorption order for the OME molecules on BP was 1.513, a value closer to 2, while n AV for the adsorption of OME molecules onto BTM was 0.8409, a value close to 1.
The AFO is widely reported in the literature, and it suggests a complex process with multiple adsorption pathways, with dynamic/different mechanism (s), while adsorption occurs [35,36]. This process presents multiple kinetic orders instead of one, represented by n AV , which usually has a fractional value [35,36]. Thus, evaluating t 1/2 and t 0.95 becomes important for comparing different kinetic models (see Table 2) [19,20,25,[33][34][35]. The t 0.95 is the time to reach 95% of total saturation, and t 1/2 is the time to reach 50%. Considering that the AFO presented the best fitness, its values for t 1/2 and t 0.95 were 8.32 min and 21.87 min, and 3.27 min and 18.65 min for BP and BTM adsorbents. It shows that the kinetic was faster for BTM, possibly due to different chemical features provoked by the doping with Si/Mg [24]. Short times to attain 95% saturation are obtained for carbon-based materials to uptake emerging organic molecules [12,14,20].

Equilibrium Isotherms Studies of OME on Biobased Adsorbents
The isotherm of adsorption is a valuable tool for better evaluating the adsorption system between the adsorbent and adsorbate [37][38][39][40][41]. There are many isotherm models, and in this work, the Langmuir, Freundlich, and Liu models were employed to study the equilibrium of adsorption between adsorbents and OME molecules [37,[42][43][44]. Freundlich's model assumes multiple layers of adsorbate covering the adsorbent. As a result, no saturation of the adsorbent is achieved, and the energy of each active site is not homogeneous, while Langmuir almost assumes the opposite. Liu is the combination of Freundlich and Langmuir models and considers the saturation of the adsorbent, a multilayer of the adsorption of adsorbate, and the activate sites of the adsorbents with different energy [39,40,44].
The isotherm curves and parameters are displayed in Figure 4 and Table 3. The fitness of the isotherm models was examined previously for the kinetics (by R 2 adj , SD, and BIC values). Considering the SD values and R 2 adj obtained from the nonlinear isotherm model fitting, high differences were observed between the models for all temperatures. In general, Liu's model provided the lowest SD and highest R 2 adj values for both adsorbents. Moreover, taking into account the BIC values, they were lowest for Liu, which is statistically the bestchosen model [14,20,34]. The Liu model assumes that the adsorbent's adsorption active sites cannot have the same energy. Therefore, the adsorbents may present active sites preferred by the OME molecules for occupation. However, at the studied condition, the saturation of the active sites should occur, unlike in the Freundlich isotherm model. Except for the isotherm at 298 K, Table 3 shows a fitting for the Liu isotherm model. This may indicate that the surface of the biobased adsorbents is likely heterogeneous, with different energy adsorption sites.

Thermodynamic Studies of OME on BP and BTM
The thermodynamics was examined using the van't Hoff approach [22], whose equilibrium constant was accessed from the best equilibrium constant obtained in the isotherms from 283 to 318 K. Table 4 shows the thermodynamic adsorption parameters for OME on biobased adsorbents. The thermodynamic data show that the adsorption process was spontaneous and favorable at the six studied temperatures (283, 293, 298, 303, 308, 313, and 318 K), with negative values of ∆G • [20,33,34,45]. Furthermore, the adsorption process was endothermic for BTM adsorbent (∆H • < 0) and exothermic for BP (∆H • > 0) [20,33,45]. The ∆H • values refer to the magnitude of the adsorption [20,33,35,45], which corresponds to a physical adsorption process since its values are <40 kJ mol −1 [35,45]; however, other mechanisms could be involved in the adsorption of OME on BP and BTM, which is further studied in the next section. Finally, for both adsorbents, the changes in the entropy (∆S • ) were positive, which indicates an increase in the randomness, and a more disorganized state of the adsorption system, after OME uptake by BP and BTM [31,32,46].

Mechanism of Adsorption
An adsorption mechanism between OME and BTM can be stated based on the biochars' physicochemical characteristics (porosity and chemical surface and functionalities) and adsorption results. The high adsorption of OME by the BTM adsorbent was achieved due to its physical features through the pore-filling mechanism and chemical interactions through H-bonding, π-π and n-π interactions, and the Lewis acid-base interaction [9][10][11][12]14] (see Figure 5). Since the biochars are very porous, physical adsorption through pore filling should be the principal mechanism involved in the process, although other mechanisms also take place in removing OME from the aqueous solution. In addition, the Mg on the carbon matrix generates dipoles in the carbon structure due to electronegativity differences that generate ion-dipole interaction with the OME molecules [18].

Synthetic Effluent Treatment Tests
The biobased adsorbents showed good efficiency in removing OME from aqueous solutions. Thus, they are expected to be effective in treating effluents containing several organic and inorganic compounds (similar to real effluents). Therefore, two synthetic

Synthetic Effluent Treatment Tests
The biobased adsorbents showed good efficiency in removing OME from aqueous solutions. Thus, they are expected to be effective in treating effluents containing several organic and inorganic compounds (similar to real effluents). Therefore, two synthetic wastewaters loaded with several drugs, and other organic and inorganic compounds (see Supplementary Table S1) were employed to test the ability of the BP and BTM to clean them up (see Figure 6).

Synthetic Effluent Treatment Tests
The biobased adsorbents showed good efficiency in removing OME from aqueous solutions. Thus, they are expected to be effective in treating effluents containing several organic and inorganic compounds (similar to real effluents). Therefore, two synthetic wastewaters loaded with several drugs, and other organic and inorganic compounds (see Supplementary Table S1) were employed to test the ability of the BP and BTM to clean them up (see Figure 6). The percentage of removal of the effluents' compounds was measured while taking into account the UV-Vis spectra area of the two synthetic effluents before and after the treatment under the band of absorption from 190 to 500 nm [10,11,19,47] (see Figure 6). The results showed that BTM adsorbent removed 62% and 36% of the total compounds from the synthetic effluents A (lowly concentrated) and B (highly concentrated), respectively, while BP adsorbent removed 53% and 25% for effluents A and B, respectively. The better BTM efficiency in removing both effluents matches the previous adsorption results The percentage of removal of the effluents' compounds was measured while taking into account the UV-Vis spectra area of the two synthetic effluents before and after the treatment under the band of absorption from 190 to 500 nm [10,11,19,47] (see Figure 6). The results showed that BTM adsorbent removed 62% and 36% of the total compounds from the synthetic effluents A (lowly concentrated) and B (highly concentrated), respectively, while BP adsorbent removed 53% and 25% for effluents A and B, respectively. The better BTM efficiency in removing both effluents matches the previous adsorption results that exhibited better performances for the BTM adsorbent. These results suggest that the adsorbents prepared in this work could be employed in real effluents carried with drugs and other organic/inorganic pollutants.

Preparation of the Adsorbents-Activated Biochars
Spruce bark waste was used to produce the adsorbents. Firstly, the biomass waste was ground, using a hammer mill, to a particle size smaller than 0.5 mm. Then, for the doped sample (with Si and Mg), 10 g of biomass was mixed with 2 g of TEOS (tetraethyl orthosilicate) and 1 g of MgCl 2 into a solution of water/ethanol (50%:50%), under vigorous stirring at room temperature for 2 h. The function of adding TEOS to MgCl 2 is the possibility of forming Si-O-Mg bonds that could affect the sorption capacity of the BRM material. After that, the mixture was placed in a drying oven overnight at 80 • C. The same procedure was used for the pristine biobased material sample but without TEOS and MgCl 2 . Next, the impregnated samples were pyrolyzed using a specially designed reactor at a temperature of 800 • C in a CO 2 flow for 1 h. After that, the temperature of the sample was increased to 10 • C/min. Finally, samples were ground using a hammer mill and sieved to a particle size < 200 µm. To wash away the remaining byproducts from the pyrolyzed carbon materials, they were washed several times with boiling de-ionized water until the pH of the wash water was equal to the pH of the de-ionized water. Hereafter, these samples were named BP (non-doped with Si/Mg) and BTM for the doped sample.

Characterization of the Biochars
The specific surface area (SSA) and micro/meso-pore structure were obtained using a sorption meter (Tristar 3000, Micromeritics Instrument Corp., Norcross, GA, USA). The samples were subjected to degasification at 180 • C for 3 h in a nitrogen atmosphere. The SSA was calculated using the Brunauer-Emmett-Teller (BET) method.
The adsorbents' surface morphology was examined by scanning electron microscopy (SEM) (55-VP, Supra, Zeiss, Jena, Germany), using an acceleration voltage of 20 kV. In addition, the Raman spectra of the adsorbents were obtained using a Bruker Bravo spectrometer (Bruker, Ettlingen, Germany).

Adsorption Studies
De-ionized water was used to prepare the OME (omeprazole) solutions and the synthetic effluents. The batch mode was employed to evaluate the applicability of the biobased adsorbents in removing OME from aqueous solutions. In addition, the effect of the solution temperature on OME adsorption was investigated. All adsorption experiments were performed using 30 mg of each biochar into 20 mL of OME, using 50.0 mL Falcon tubes [18][19][20]. OME initial solution concentrations from 80 to 420 mg L −1 were employed in the experiments for isotherms studies. The kinetic OME removal on biochars was studied, varying contact time from 0 to 180 min, with an OME initial concentration of 300 mg L −1 . The effect of temperature was measured, and thermodynamic studies were performed, at temperatures from 283 to 318 K. All adsorption experiments were performed at a constant shaking speed of 200 rpm. After adsorption, the residual solutions of OME were quantified using a UV-Visible spectrophotometer (Shimadzu 1800) at a maximum wavelength of 298 nm. The removal capacity and the percentage of OME removal are obtained from Supplementary Equations (S1) and (S2), respectively.

Kinetics, Equilibrium, and Thermodynamics Studies
The kinetics were studied by employing PFO, PSO, and AFO models. Three isotherm models, i.e., the Freundlich, Langmuir, and Liu models, were employed for the equilibrium study. The thermodynamics was examined from van't Hoff approach [21], whose equilibrium constant was accessed from the best equilibrium constant obtained in the isotherms from 283 to 318 K. Information on these models and their fitness suitability are shown in the Supplementary Materials.

Synthetic Effluents
Two simulated pharmaceutical effluents, which consisted of drugs and other organic/inorganics compounds found in hospital wastewater, were prepared with de-ionized water [9][10][11]. The compositions and concentrations of the components of the effluents are presented in Supplementary Table S1. The purpose of using simulated effluents is to test the sorption capacities of the adsorbents for the removal of the mixture of several compounds simulating real effluents.

Conclusions
In this work, we developed adsorbents with improved emerging contaminant (OME) adsorption skills. TEOS and MgCl 2 made carbon-based composite adsorbents as Si and Mg sources. The physicochemical characterization proved that successfully incorporating Si and Mg modified the carbon structure, yielding better adsorptive properties. The addition of Si and Mg in the carbon structure helped to increase the number of mesopores. The EDS quantification of the elements indicated 18.4% and 10.7% of Si and Mg, respectively. When tested as adsorbents, the AFO model better fitted the kinetic, and the equilibrium data were better fitted to the Liu isotherm model. The adsorbent sample doped with both chemicals (Si and Mg) presented a faster kinetic, reaching 95% of their saturations at 21.87 and 18.65 min for BP and BTM adsorbents, respectively. The maximum adsorption capacities obtained from the Liu model at 298 K were 91.54 and 249.0 mg g −1 for BP and BTM, respectively. The better adsorptive properties of the BTM were due to different chemical features provoked by the doping process. The thermodynamic data showed that the adsorption of OME on biobased adsorbents was spontaneous and favorable at the range of studied temperatures, with the magnitude of the adsorption corresponding to the physical adsorption process. The adsorbents were applied in treating synthetic hospital effluents containing different pharmaceuticals, organics, and inorganic salts and presented a high percentage of removal (up to 62%). The results of this work have shown that the composite between spruce bark biomass and Si/Mg was an efficient adsorbent for emerging pollutants removal. Therefore, we hope this report can help open new strategies for developing sustainable and effective adsorbents to tackle water pollution.